Conventional pickup truck mounted snow plow assemblies have a mount frame that attaches to the truck frame below and behind the front bumper, and a snow plow frame that removably attaches to the mount frame. When not in use the snow plow frame is detached from the mount frame and stored; the mount frame remains on the truck frame but is generally unobtrusive as it is below and behind the front bumper.
A conventional snow plow frame has a lift frame and an A-frame. The lift frame removably attaches at its lower ends to the mount frame, and generally extends forwardly and upwardly from the mount frame. The A-frame is pivoted at its rearward end to the lower ends of the lift frame for pivoting about a transverse horizontal lift axis. A plow blade is pivoted to the A-frame at its forward end for pivoting about a vertical axis. Hydraulic cylinders are attached on one end to the blade and on the other end to the A-frame to pivot the blade about the vertical axis. The plow blade may also be pivoted to the A-frame for pivoting about a transverse horizontal blade trip axis, in the event that the snow plow employs a blade trip, or alternatively, a lower edge of the blade may be pivoted to the balance of the blade for pivoting about a transverse horizontal edge trip axis, in the event that the snow plow employs an edge trip. A hydraulic cylinder is operable between the lift frame and the A-frame to pivot the A-frame about the transverse horizontal lift axis and hence raise and lower the blade. There are at least two different types of lift arrangements.
One type of lift arrangement has a hydraulic cylinder attached on one end to the lift frame and attached on the other end to the A-frame. In this arrangement, retracting the cylinder directly raises the A-frame and blade, and extending the cylinder directly lowers the A-frame and blade. The other type of lift arrangement has a lift arm pivoted to the lift frame, a chain or cable or other tethering device attached on one end to the free end of the lift arm and attached on the other end to the A-frame, and a hydraulic cylinder attached on one end to the lift frame and attached on the other end to the lift arm. In this arrangement, extending the cylinder raises the A-frame and blade via the lift arm and chain, and retracting the cylinder lowers the A-frame and blade via the lift arm and chain.
Over the years a number of different hitching mechanisms have been proposed to allow an operator to more quickly and easily hitch the snow plow frame to the mount frame. Some examples of hitch assemblies are shown in the assignee's U.S. Pat. No. Re. 35,700, U.S. Pat. Nos. 6,928,757, 6,711,837, 6,526,577, 5,353,530, 7,797,859, 7,681,334, 7,430,821, 6,944,978, 6,615,513, 6,393,737, 6,276,076, and 6,178,669, the disclosures of which are hereby incorporated by reference herein as if fully set forth in their entirety.
Despite the advances made in the area of hitching mechanisms over the years, further improvement is nevertheless desired, as it also is for snow plows in general.